THE CLIMATE KELPIE BLOG: Learning from the past, looking to the future

Posted by BCG on 4th May 2017

Wimmera and Mallee farmers are rejoicing after excellent rainfall in recent weeks, and on the back of a remarkable 2016 season, many farmers are currently sitting on healthy levels of sub-soil moisture.

While comparing seasons is something we all do, no two seasons are identical and the message remains to ‘prepare, don’t predict’.

When it comes to ‘the autumn break’ in April, many times the result has been minimal to nothing. But this year’s start resembles that of 1999 and 2014, when April rainfall was not only plentiful but perfectly timed, and as the saying goes ‘the difference between a good and a bad season is one or two well-timed rains.’

While the autumn ‘breaks’ were similar in 1999 and 2014, the spring in both of these seasons were less than ideal. But, we can learn from these years and apply those learnings going into 2017.

In 1999, there was virtually no rain between early September and mid-October in the southern Mallee, and with no sub-soil moisture, moisture stress became evident.

In 2014, Woomelang received 71mm in April which was one of the highest rainfall totals for the area in April. When rainfall didn’t continue in 2014, many crops suffered from moisture stress in spring and growers had to try and recoup some income by cutting hay, or ride it out and hope that grain yields would be better than expected.

The great start and unreliable spring in these years highlighted that there is no substitute for stored soil moisture. Growers were exceptionally busy this summer not only with a late harvest, but out spraying as many summer weeds and volunteers as possible.

While the forecasting models are currently leaning towards a dry spring for 2017, caution should be taken because models at this time have low skill (accuracy).

While the prediction for El Niño in 2014 did not quite eventuate, the dry spring did bear the hallmarks of El Niño climate patterns. Current modelling for 2017 is also indicating that an El Niño could form in the later portion of the year. The Bureau of Meteorology’s latest outlook specifies that May to July is likely to be below average for large proportions of Australia, but skill level at this time is still low.

So, what can we learn from 2014 that may be useful in decision making this year?

Now that your cropping plan has been carefully formulated, don’t get caught up in short term seasonal events like an early break. Having some flexibility in your plan can be good but there are good reasons you made your original decision.

Sowing canola in paddocks with sub-soil moisture is one way of reducing risk given the variable nature associated.

If you decide to take the opportunity to sow earlier, remember to get spring wheat varieties in the ground within 5 to 7 days of the optimal date to mitigate frost risk. Frost in August 2014 caused significant damage, ensuring you have a spread of flowering days reduces risk.

While we all have our fingers crossed for a favourable season, plans and contingencies are always present to assist in decision making during the season. Prepare, don’t predict.